Stabilization of monomeric 1, 1-dicyano ethylene



Patented Apr. 19, 1949 STABILIZATION F MONOMEBIC LI -DI- E'I'HYLENE Ohio, minor to The B. 1''. New York, N. Y. a com- OYANO Harry Gilbert, Akron, Goodrich Company,

ration of New York No Drawing. Application Claims. (ci. zoo-405.0)

This invention relates to stabilized monomeric 1,1-dicyano ethylene and relates more particular to the use of oxides and sulfides oi phosphorous for inhibiting the polymerization of monomeric 1,1-dicyano ethylene.

In copending applications Serial Nos. 775,149, filed September 12, 1947, and 785,520, filed November 12, 1947, methods for the preparation'of 1,1-dicyano ethylene are disclosed. It is also disclosed in said copending applications, that 1,1-dicyano ethylene undergoes autopolymerization so that special precautions are necessary in order to inhibit such autopolymerization and to obtain the 1,1-dicyano ethylene in monomeric form and to keep it in the monomeric form during periods of storage. Many of the most commonly used stabilizing substances, such ashydroquinone, copper, copper salts, tertiary butyl carbinol, phenyl-betanaphthylamine and the like are unsatisfactory for inhibiting the polymerization of 1,1-dicyano ethylene.

I have now found, however, that the sulfides and oxides of Example I, using 2% type container and phosphorous phosphorous are excellent stabilizers for monomeric 1,1-dicy-ano ethylene. The preierred oxide and sulfide of phosphorous have the formula P205 and P255, that is, where the phosphorous has a valence of 5. However, the other sulfides and oxides of phosphorous, that is, those in which the phosphorous has a valence of 2, 3 and 4, are also excellent stabilizers for 1,1-dicyano ethylene and are included within the scope of this invention. Among such other oxides and sulfides are the following: phosphorous tri-oxide (P203 or P400); phosphorous tetra-oxide (P204); phosphorous di-sulfide (Pass or PS2) and phosphorous tri-sulfide (P480 or P282). It is to be understood that the stabilizing eilect of the abovelisted compounds occurs regardless of the method of preparation of the 1,1-dicyano ethylene.

The oxides and sulfides of phosphorous may be present in any orally, and especially for phosphorous pentoxide and phosphorous pentasulfide, small amounts of approximately 0.01 to 5%. more preierably 0.1% to 2% based on the weight of the monomer, are sufilcient to inhibit the polymerization oi mono! mhelric 1,1-dicyano ethylene for long periods 0! t e.

The following example illustrates the use of the oxides and sulfides oi phosphorous asstabilizers for 1,1-dicyano ethylene according to this invention:

Example I Monomeric 1,1-dicyano ethylene containing 2% by weight of phosphorous pentoxide was stored in silica glass containers at a temperature 0: 20 C.

selitembel' 19,1947, 775,150

which in this case required 55 days. A control sample of monomeric 1,1-dicyano polymerized to a solid material in only even when'kept at temperatures as Example 11 A second set of samples were prepared as in by weight of phosphorous pentasulfide as the stabilizing agent. The 1.1- dicyano ethylene remained in the stable form for a period of 55 days at 20 C.

, The stabilized composition of 1,1-dicyano ethylene may also be stored in plastic, metal or other in addition to glass. Furthermore, it may be stored at elevated temperatures with but little decrease in the time the composition remains stable.

Also, the other oxides and sulfides of phosphorous mentioned hereinabove exhibit stabilizing effects on monomeric 1,1-dicyano ethylene which are in general equal to phosphorous-pentoxide pentasulfide.

While certain preferred manners of performing the invention have been disclosed, it is not intended to limit the invention thereto, for numerous variations will be apparent to those skilled in the art and are included within the scope of low as 10 C.

' the invention as defined in the appended claims.

desired amount, although gen- The samples were observed daily until the 1,1- dicyano ethylene became unstable (1. e., darkens and polvmerizes to a non-flowing material).

I claim:

l. Monomeric 1,1-dicyano ethylene containing as a stabilizer a member of the class consisting of the oxides and sulfides of phosphorous.

2. Monomeric 1,1-dicyano ethylene containing an oxide of phosphorous as a stabilizer.

3. Monomeric 1,1-dicyano ethylene-containing a sulfide oi phosphorous as a stabilizer.

4. Monomeric 1,1-dicyano ethylene containing phosphorous pentoxide as a stabilizer.

5. Monomeric 1.1-dicyano ethylene containing phosphorous pentasulfide as a stabilizer.

- HARRY GILBERT.

REFERENCES CITED The following references are oi'record in the file of this patent:

UNITED STATES PATENTS Number Date V Van der'Burs.

(1922). Ephraim, "Inorganic Chemistry" (edited Thorne et al.. 4th ed). pales I10. 718. I19 (194'?) Rec. Trav. Chim.. vol. 41, page 23 1'1 hours at 20 C. and 

